Structure of driving unit in drum type washing machine

ABSTRACT

Structure of driving unit in a drum type washing machine including a tub mounted inside of a cabinet, a drum mounted inside of the tub, a shaft connected to the drum mounted inside of the tub for transmission of a driving force from a motor to the drum, a front bearing and a rear bearing mounted on an outer circumference of the shaft at opposite end portions thereof respectively, a bearing housing built in a central portion of a rear wall of the tub for supporting the front bearing, a rotor composing the motor together with the rotor, and coupled to the rear end portion of the shaft, a stator fixed to the tub rear wall inward of the rotor to compose the motor together with the rotor, a connector serration coupled to the outer circumference of the shaft in front of the rear bearing and fixed to the rotor, for transmission of a rotating power from the rotor to the shaft, and a bearing bracket fixed to the rear wall of the tub to cover an outside of the rotor and support the rear bearing, thereby reducing noise, repair and power loss, by improving a structure of a driving unit, improving a product reliability, by improving a washing capability, and improving a productivity by improving workability in fabrication of components of the driving unit.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a drum type washing machine, and moreparticularly, to a structure of a driving unit in a drum type washingmachine.

2. Background of the Invention

In general, a drum type washing, making washing by using frictionbetween a drum rotated by a motor and laundry in a state detergent,washing water, and the laundry are introduced into the drum, provideseffects of beating and rubbing washing, but gives almost no damage tothe laundry, and shows no entangling of the laundry. A structure of arelated art drum washing machine will be explained with reference toFIG. 1. FIG. 1 illustrates a longitudinal section of a related art drumtype washing machine, provided with a tub 2 mounted inside of a cabinet1, a drum 3 rotatably mounted on a central portion of inside of the tub2. There is a motor 5 a under The tub 2 connected with a pulley 18.There is a drum shaft connected to a rear of the drum 3, to which a drumpulley 19 is coupled. And, the drum pulley 19 on the drum shaft and themotor pulley 18 connected to the motor 5 a are connected by a belt 20for transmission of power. And, there is a door 21 in a front part ofthe cabinet 1, with a gasket 22 between the door 21 and the tub 2. Thereis a hanging spring between an inside of an upper portion of the cabinet1 and an outside of an upper portion of the tub 2, and a friction damper24 between an inside of a lower portion of the cabinet 1 and a lowerside of an outside of the tub 2 for damping vibration of the tub 2generated during spinning.

However, the related art washing machine has the following disadvantagessince driving power of the motor 5 a is transmitted to the drum 3through the motor pulley 18, and the drum pulley 19, and the belt 20connecting the motor pulley 18 and the drum pulley 19.

First, there is a loss of energy in a course of driving powertransmission because the driving power is transmitted from the motor 5 ato the drum 3, not directly, but through the belt 20 wound around themotor pulley 18 and the drum pulley 19.

And, the driving power transmission from the motor 5 a to the drum 3,not directly, but through many components, such as the belt 20, themotor pulley 18, and the drum pulley 19, causes much noise in the courseof power transmission.

The lots of components required for transmission of driving power fromthe motor 5 a to the drum 3, such as the motor pulley 18, the drumpulley 19 and the belt 20, require many assembly man-hours. And, themore the number of components required for transmission of driving powerfrom the motor 5 a to the drum 3, the more number of spots which requirerepair, and the more frequent at which repair required.

In summary, the indirect driving power transmission from the motor 5 ato the drum 3 through the motor pulley, the drum pulley, and the beltrequires many repair, has much noise, waste of energy, and results in adeterioration of a washing capability.

Moreover, the tub 2 of stainless steel in general in the related artdrum washing machine is expensive, has a poor formability, and is heavy.

SUMMARY OF THE INVENTION

Accordingly, the present invention is directed to a structure of adriving unit in a drum type washing machine that substantially obviatesone or more of the problems due to limitations and disadvantages of therelated art.

An object of the present invention is to provide a structure of drivingunit in a drum type washing machine, which can reduce noise, repair andwaste of energy, and moreover, improve washing capability.

Another object of the present invention is to provide a structure ofdriving unit in a drum type washing machine, which has an improvedsupporting force.

Additional features and advantages of the invention will be set forth inthe description which follows, and in part will be apparent from thedescription, or may be learned by practice of the invention. Theobjectives and other advantages of the invention will be realized andattained by the structure particularly pointed out in the writtendescription and claims hereof as well as the appended drawings.

To achieve these and other advantages and in accordance with the purposeof the present invention, as embodied and broadly described, thestructure of a driving unit in a drum type washing machine having a tubmounted in a cabinet, a drum mounted in the tub, a shaft fixed to thedrum for transmission of driving power from the motor to the drum, andbearings mounted on an outer circumference of the shaft at opposite endportions thereof, includes a metallic bearing housing at a centralportion of a rear wall of the tub for supporting the bearings mounted onthe outer circumferences of opposite end portions of the shaft.

In other aspect of the present invention, there is provided a structureof driving unit in a drum type washing machine including a tub mountedinside of a cabinet, a bearing housing built in a central portion of arear wall of the tub for supporting a bearing therein, a shaft connectedto a drum mounted inside of the tub for transmission of a driving forcefrom a motor to the drum, bearings mounted on an outer circumference ofthe shaft at opposite end portions thereof respectively, a rotor coupledto a rear end of the shaft, a stator provided inward of the rotor fixedto the tub rear wall, a connector provided between the shaft and therotor for transmission of a rotating force from the rotor to the shaftfor rotating the shaft and the rotor together, and a supporter fittedbetween the rear wall of the tub and the stator for supporting thestator and maintaining a concentricity when the stator is mounted to thetub rear wall.

In another aspect of the present invention, there is provided astructure of driving unit in a drum type washing machine including a tubof plastic mounted inside of a cabinet, a metallic bearing housinginserted and built in a central portion of a rear wall of the tub havingsteps of “┐” and “└” forms on an inner circumference for supportingbearings therein, a shaft connected to a drum mounted inside of the tubfor transmission of a driving power from a motor to the drum, having afront end portion fixed to a spider in the drum rear wall, a brassbushing press fit on a region of the shaft from a portion exposed inrear of the spider to the front bearing for prevention of rusting of theshaft, and steps on an outer circumference thereof for fixing mountingpositions of the front bearing and the rear bearing on the shaft,bearings mounted on the outer circumference of the shaft at opposite endportions thereof respectively, a rotor of steel or steel alloy platecoupled to the rear end portion of the shaft, including a bent portionformed along a circumference thereof having a setting surface forsupporting magnets fitted to an inside of a front portion of a sidewallextended forward from a periphery of a rear wall, and a hub at a centerof the rear wall having a through hole for a fastening member, such as abolt, for coupling the rotor to the shaft, a plurality of cooling finsformed around the hub in a radial direction each with a length forblowing air toward the stator when the rotor is rotated for cooling downa heat generated at the stator, an embossing between adjacent coolingfins on the rear wall of the rotor for reinforcing the rotor, and adrain hole in each of the embossings, for drain of water, a statorcomposing the motor together with the rotor, fixed to the tub rear wallinward of the rotor, a connector of plastic provided between the shaftand the rotor for transmission of a rotating force from the rotor to theshaft for rotating the shaft and the rotor together, and a supporterfitted between the rear wall of the tub and the stator for supportingthe stator and maintaining a concentricity when the stator is mounted tothe tub rear wall.

In further aspect of the present invention, there is provided astructure of driving unit in a drum type washing machine including a tubmounted inside of a cabinet, a drum mounted inside of the tub, a shaftconnected to the drum mounted inside of the tub for transmission of adriving force from a motor to the drum, a front bearing and a rearbearing mounted on an outer circumference of the shaft at opposite endportions thereof respectively, a bearing housing built in a centralportion of a rear wall of the tub for supporting the front bearing, arotor composing the motor together with the rotor, and coupled to therear end portion of the shaft, a stator fixed to the tub rear wallinward of the rotor to compose the motor together with the rotor, aconnector serration coupled to the outer circumference of the shaft infront of the rear bearing and fixed to the rotor, for transmission of arotating power from the rotor to the shaft, and a bearing bracket fixedto the rear wall of the tub to cover an outside of the rotor and supportthe rear bearing.

In a still further aspect of the present invention, there is provided astructure of driving unit in a drum type washing machine including a tubof plastic mounted inside of a cabinet, a metallic bearing housinginserted to built in a central portion of a rear wall of the tub havingsteps on an inner circumference for supporting bearings therein, a shaftconnected to a drum mounted inside of the tub for transmission of adriving power from a motor to the drum, having a front end portion fixedto a spider in the drum rear wall, and a brass bushing press fit on aregion of the shaft from a portion exposed in rear of the spider to thefront bearing for prevention of rusting of the shaft, bearings mountedon the outer circumference of the shaft at opposite end portions thereofrespectively, a rotor of steel or steel alloy plate coupled to the rearend portion of the shaft, including a bent portion formed along acircumference thereof having a setting surface for supporting magnetsfitted to an inside of a front portion of a sidewall extended forwardfrom a periphery of a rear wall, and a hub at a center of the rear wallhaving a through hole for a fastening member, such as a bolt, forcoupling the rotor to the shaft, a plurality of cooling fins formedaround the hub in a radial direction each with a length for blowing airtoward the stator when the rotor is rotated for cooling down a heatgenerated at the stator, an embossing between adjacent cooling fins onthe rear wall of the rotor for reinforcing the rotor, and a drain holein each of the embossings, for drain of water, a stator composing themotor together with the rotor, fixed to the tub rear wall inward of therotor, a connector of plastic provided between the shaft and the rotorfor transmission of a rotating force from the rotor to the shaft forrotating the shaft and the rotor together, a supporter fitted betweenthe rear wall of the tub and the stator for supporting the stator andmaintaining a concentricity when the stator is mounted to the tub rearwall, and a bearing bracket fixed to the rear wall of the tub to coveran outside of the rotor and support the rear bearing.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory and areintended to provide further explanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this specification, illustrate embodiments of the invention andtogether with the description serve to explain the principles of theinvention:

In the drawings:

FIG. 1 illustrates a longitudinal section of a related art drum typewashing machine;

FIG. 2A illustrates a longitudinal section of a drum type washingmachine in accordance with a first preferred embodiment of the presentinvention;

FIG. 2B illustrates a detailed enlarged view of “A” part in FIG. 2A;

FIG. 3 illustrates a perspective view with a partial cut away view ofthe rotor in FIG. 2;

FIG. 4 illustrates an enlarged perspective view of “B” part in FIG. 3;

FIG. 5 illustrates a perspective view of a bottom in FIG. 3;

FIG. 6 illustrates a perspective view of the stator in FIG. 2;

FIG. 7 illustrates a perspective view of the connector in FIG. 2;

FIG. 8 illustrates a perspective view of a bottom in FIG. 7; and,

FIG. 9 illustrates a longitudinal section of a driving unit in a drumtype washing machine in accordance with a second preferred embodiment ofthe present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Reference will now be made in detail to the preferred embodiments of thepresent invention, examples of which are illustrated in the accompanyingdrawings. A first preferred embodiment of the present invention will beexplained in detail with reference to FIGS. 2A˜8. FIG. 2A illustrates alongitudinal section of a drum type washing machine in accordance with afirst preferred embodiment of the present invention, FIG. 2B illustratesa detailed enlarged view of “A” part in FIG. 2A, FIG. 3 illustrates aperspective view with a partial cut away view of the rotor in FIG. 2,FIG. 4 illustrates an enlarged perspective view of “B” part in FIG. 3,FIG. 5 illustrates a perspective view of a bottom in FIG. 3,FIG. 6illustrates a perspective view of the stator in FIG. 2, FIG. 7illustrates a perspective view of the connector in FIG. 2, and FIG. 8illustrates a perspective view of a bottom in FIG. 7.

The drum type washing machine in accordance with a first preferredembodiment of the present invention includes a tub 2 of plastic mountedinside of the cabinet 1, a drum 3 mounted in the tub 2, a shaft 4 fixedto the drum 3 for transmission of driving power from a motor 5 to thedrum 3, bearings 6 a and 6 b fitted on outer circumference of the shaft4 at both ends thereof, and bearing housings 7 of metal fitted tosupport the bearings 6 a and 6 b at a central portion of a rear wall 200of the tub 2. The bearing housing 7 of metal is formed as a unit withthe tub rear wall 200 by an inserted injection molding in the injectionmolding of the tub 2 of plastic. The bearing housing 7 is preferablyformed of aluminum. The bearing housing 7 has steps 8 a and 8 b forholding the front bearing 6 a and the rear bearing 6 b fitted in innercircumferences of the bearing housing 7 for preventing the bearings 6 aand 6 b from being fallen off. Of the steps 8 a and 8 b formed on theinner circumferences of the bearing housing 7, the front step 8 a has aform of “┐” for supporting a rear end portion of the front bearing 6 afitted to a front end of an outer circumference of the shaft 4, and therear step 8 b has a form of “└” for supporting a front end portion ofthe rear bearing 6 b fitted to a rear end portion of the shaft 4. And,there are positioning steps 400 a and 400 b on outer circumferences ofthe shaft 4 disposed inside of the bearing housing 7 which transmitsdriving power from the motor 5 to the drum 3, for fixing mountingpositions of the front bearing 6 a and the rear bearing 6 b on the shaft4. A front end of the shaft 4 is coupled to a spider 10 in a rear wallof the drum 3, a region of the shaft 4 from a portion exposed in rear ofthe spider 10 to the front bearing 6 a has a bushing 11 of brass pressfit thereon for prevention of rusting, and there is a sealing member 12on an outer surface of the bushing 11 for preventing ingress of watertoward the bearing. There is a rotor 13 of a direct coupling type motor5 fixed to a center of a rear end of the shaft 4, and a stator 14 of acrown form, consisting the direct coupling type motor 5 together withthe rotor 13, fixed to the rear wall 200 inside of the rotor 13.

Referring to FIGS. 3˜5, the rotor 13 of steel or steel alloy plateincludes a bent portion formed along a circumference thereof having asetting surface 130 for supporting magnets 13 c fitted to an inside offront of a sidewall 13 b extended forward from a periphery of a rearwall 13 a, and a hub 132 at a center of the rear wall 13 a having athrough hole 131 for fastening members 15 a, such as bolts, for couplingthe rotor 13 to the shaft 4. An overall form of the rotor 13 ispreferably formed by press forming. There are a plurality of coolingfins 133 each formed to have a preset length in a radial directionaround the hub 132 of the rotor 13 for blowing air toward the stator 14during rotation of the rotor 13 for cooling heat generated at the stator14.

The cooling fins 133 are formed by lancing, to bend the cooling fins 133at a right angle to the rear wall toward the opening to leave throughholes 134 for ventilation. There is an embossing 135 between adjacentcooling fins 133 with a drain hole 136 therein for draining water. Thereare fastening holes 137 for fastening a connector 16 to the rotor 13 andpositioning holes 138 for positioning an assembly position of theconnector 16 around the through hole 131 in the hub 132 of the rotor 13at fixed intervals, which connector 16 is serration coupled to an outercircumference of a rear end portion of the shaft 4 exposed to rear ofthe rear bearing 6 b. The connector 16 is formed of resin having avibration mode different from the rotor 13 of steel or steel alloyplate, and also serves as a bushing for the rotor 13. As shown in FIGS.2B, 7 and 8, the connector 16 has fastening holes 162 to correspond tothe fastening holes 137 in the hub 132 of the rotor 13 around acircumferential direction of the a peripheral region and a dowel pin 160between adjacent fastening holes 162 as a unit with the connector 16 forinsertion in the positioning hole 138 in the rotor 13 for self alignmentof the fastening holes 137 and 162 in the rotor 13 and the connector 16,respectively. The connector 16 has a serration in an insidecircumference of the hub 163 matched to the serration in the rear end ofthe shaft 4, and reinforcing ribs 161 on outer circumference of the hub163 for reinforcing the hub 163. There is a hub 201 on the rear wall 200of the tub 2 having the bearing housing 7 inserted therein when the tubis injection molded, and fastening bosses 202 on an outer side of thehub 201 along a circumferential direction at fixed intervals forfastening the stator 14 to the rear wall 200 of the tub 2. There is asupporter 17 between the rear wall 200 of the tub 2 and the stator 14,of a form almost identical to an outline of the tub rear wall 200, fixedto the tub rear wall 200 when the stator 14 is assembled for supportingthe stator 14 and maintaining concentricity of the stator 14. Thesupporter 17 has a fore end brought into a close contact with an insideof ribs 203 at one side of the tub rear wall 200, and a rear end broughtinto a close contact with an outer circumference of a rear end of thebearing housing 7 which is not enclosed by the hub 132, but exposed. Inthe meantime, as shown in FIGS. 2B and 6, the stator 14 includes amagnetic core 145 of segregated layers of magnetic material, a frame 140of resin coated on the magnetic core 145, a coil 142 wound around eachof winding parts 141 on an outer circumference of the frame 140, andfastening ribs 143 on an inside of the frame 140 for fastening thestator 14 to the tub rear wall 200.

The operation of the driving unit in a drum type washing machine inaccordance with a first preferred embodiment of the present inventionwill be explained. Upon causing rotation of the rotor 13 by making acurrent to flow to the coils 142 of the stator 14 in a sequence underthe control of a motor driving controller(not shown) fitted on a panel,the shaft 4 serration coupled with the connector 16 fixed to the rotoris rotated, together with the drum 3 as the power is transmitted to thedrum 3 through the shaft 4.

In the meantime, the drum type washing machine having the driving unitof the present invention applied thereto serves as follows. The tub 2 ofthe drum type washing machine of the present invention, formed of aplastic with an excellent heat resistance, is light and has a goodformability as the tub 2 is injection molded. Since the bearing housing7 in the drum type washing machine of the present invention is formed ofa metal, such as aluminum and the like, the bearing housing 7 isapplicable to a drum type washing machine having a drying cycle as thebearing housing shows no thermal deformation. And, since the metallicbearing housing 7 of the present invention is formed integrated with thetub 2 by inserting the bearing housing 7 in the hub 201 on the tub rearwall 200 before the tub 2 of plastic is injection molded, a separatestep for assembling the bearing housing 7 to the tub rear wall 200 canbe omitted, which simplifies an assembly process, that reduces assemblyman-hours. The “┐” form of the step 8 a in a front portion of an innercircumference of the bearing housing 7 and the “└” form of the step 8 bin a rear portion of an inner circumference of the bearing housing 7permit to support a rear end of the front bearing 6 a and a fore end ofthe rear bearing 6 b mounted on outer circumference of the shaft 4 atboth end portions thereof. That is, the steps 8 a and 8 b on innercircumferences of the metallic bearing housing 7 on both sides thereofprevent both bearings 6 a and 6 b from being fallen off the bearinghousing 7. The positioning steps 400 a and 400 b on outer circumferencesof the shaft 4 at front and rear portions thereof permit easypositioning of the front bearing 6 a and the rear bearing 6 b on theshaft 4 in the assembly. The front end portion of the shaft 4 is coupledto the spider 10 in the rear wall, and the brass bushing 11 press fit tothe region from the exposed portion outside of the spider 10 of theshaft 4 to the front bearing 6 a prevents rusting of the shaft 4. Thesealing member 12 outside of the bushing 11 prevents ingress of watertoward the bearing.

In the meantime, the rotor 13 of the direct coupling type motor 5 ismounted on a center of the rear end portion of the shaft 4, with thestator 14 disposed on inner side of the rotor, wherein the bend parthaving the magnet setting surface 130 is formed along a circumferentialdirection of the sidewall 13 b extended forward from a periphery of therear wall 13 a of the rotor 13, for supporting the magnets 13 c when themagnets 13 c are fitted to an inside surface of the rotor 13, tofabricate the rotor with easy. The through hole 131 of the hub 132 at acenter of the rear wall 13 a of the rotor 13 permits the fasteningmember 15 b, such as a bolt or the like, to pass therethrough forfastening the rotor 13 to the shaft 4, and the plurality of cooling fins133 around the hub 132 of the rotor 13 in a radial direction with alength blow air toward the stator 14 during rotation of the rotor 13 forcooling down a heat generated at the stator 14. The cooling fins 133 areformed by lancing, to direct toward the opening of the rotor 13, and toleave through holes 134 for ventilation. The rotor 13 of steel or steelalloy plate is formed by pressing, which shortens a fabrication timeperiod, that improves a productivity. The embossing 135 between theadjacent cooling fins 133 of the rear wall 13 a of the rotor 13 improvesan overall strength of the rotor 13, and the drain hole 136 in theembossing 135 drains water.

In the meantime, the fastening holes 137 for fastening the connector andthe positioning holes 138 for fixing an assembly position of theconnector 16 around the through hole 131 in the hub 132 of the rotor 13permits an easy assembly of the connector 16 to the rotor, whichconnector 16 is serration coupled to the outer circumference of the rearend portion of the shaft 4 exposed to rear of the rear bearing 6 b. Thatis, once the dowel pins 160 on the connector 16 are inserted in thepositioning holes 138 in the rotor 13, the fastening holes 137 and 162in the rotor 13 and the connector 16 are matched automatically, and byfastening the fastening members 15 c through the fastening holes 137 and162 in the rotor 13 and the connector 16, the connector 16 and the rotor13 can be assembled with easy. The connector 16 serves to damp vibrationfrom the rotor 13 to the shaft 4 as the connector 16 injection molded ofa resin has a different vibration mode from the rotor 13 of steel orsteel alloy plate. The serration 164 in the inner circumference of thehub 163 of the connector 16 is fit to the serration 400 in the rear endportion of the shaft 4, to transmit the rotating force of the rotor 13to the shaft, directly. The reinforcing ribs 161 on an outercircumference of the hub 163 of the connector 16 reinforce the hub 163.

In the meantime, the fastening bosses 202 along a circumference on anouter side of the hub 201 on the rear wall 200 of the tub 2 at fixedintervals permits to fix the stator 14 to the rear wall 200 of the tub 2by using the fastening boss 202. The supporter 17 between the rear wall200 of the tub 2 and the stator 14 having a form almost identical to theoutline of the rear wall 200 for being fixed to the rear wall 200 of thetub 2 when the stator 14 is fastened permits the stator 14 beingsupported and maintained of concentricity. That is, once the supporter17 is fastened to the fastening bosses 204 on the tub rear wall 200, thefore end of the supporter 17 is brought into close contact with aninside surface of the ribs 203 at one side of the tub rear wall 200 andthe rear end of the supporter 17 is brought into close contact with theouter circumference of the rear end portion of the bearing housing 7 ata central portion of the tub rear wall 200, which can not be enclosed,but exposed, by the hub 132, such that the supporter 17 supports thestator 14 as well as maintains a concentricity of the stator 14.

The structure of a driving unit in a drum type washing machine inaccordance with a first preferred embodiment of the present inventionhas the following advantages.

The motor direct coupling structure of the drum type washing machine inaccordance with a first preferred embodiment of the present inventionpermits to reduce repair, and power loss.

The bearing housing of metal in the drum type washing machine inaccordance with a first preferred embodiment of the present inventionshows no thermal deformation, that allows to apply to a product having adrying function.

The rotor of steel or steel alloy plate formed by pressing in the drumtype washing machine in accordance with a first preferred embodiment ofthe present invention requires a very short fabrication time period,with an improved productivity, because the steel or steel alloy platepressing has an excellent formability.

And, the magnet setting surface on the rotor of the present inventionimproves a workability in fitting the magnets, and the drain holes, thecooling fins, and the through holes provided to the rotor can preventoverheating of the motor, improve a reliability of the motor, andprolong a lifetime of the motor.

And, the connector having a vibration mode different from the rotor inthe drum type washing machine of the present invention can attenuate thevibration transmitted from the rotor to the shaft, and the supporter cansupport the stator and maintain a concentricity of the stator.

A driving unit in a drum type washing machine in accordance with asecond preferred embodiment of the present invention will be explainedwith reference to FIGS. 3˜9, in detail. FIG. 9 illustrates alongitudinal section of a driving unit in a drum type washing machine inaccordance with a second preferred embodiment of the present invention.The rotor, the stator and the connector in the second preferredembodiment of the present invention are identical to those of the firstembodiment, to which the same names and reference symbols are given, andwill be explained with reference to FIGS. 3˜8.

The drum type washing machine in accordance with a second preferredembodiment of the present invention includes a tub 2 mounted inside of acabinet 1, a drum 3 mounted inside of the tub 2, a shaft 4 connected tothe drum mounted inside of the tub 3 for transmission of a driving forcefrom the motor 5 to the drum, a front bearing 6 a and a rear bearing 6 bmounted on outer circumferences of the shaft 4 at both end portionsthereof respectively, a bearing housing 7 built in a central portion ofthe rear wall 200 of the tub 3 for supporting the front bearing 6 a, arotor 13 coupled to the shaft 4, a stator 14 provided inward of therotor 13 coupled to the tub rear wall 200, a connector 16 serrationcoupled to an outer circumference of the shaft 4 in front of the rearbearing 6 b and fixed to the rotor 13 for transmission of a rotatingforce of the rotor 13 to the shaft 4, a supporter 17 fitted between therear wall 200 of the tub 2 and the stator 14 for supporting the statorand maintaining a concentricity when the stator is mounted to the tubrear wall 200, and a bearing bracket 9 fixed to the tub rear wall 200for covering outside of the rotor 13 and supporting the front endportion of the rear bearing 6 b. The tub 2 is formed of plastic, and hasan opened front and a closed rear wall 200 of which thickness is greaterthan a thickness of a sidewall, and the bearing housing 7 at the centralportion of the rear wall 200 of the tub 2 is formed of a metal, whereinthe bearing housing 7 is insert injection molded when the plastic tub 2is injection molded, such that the bearing housing 7 is integrated withthe tub rear wall 200. The bearing housing 7 is preferably formed of analuminum alloy.

In the meantime, there is a step 7 a on an inner circumference of themetallic bearing housing 7 for supporting the front bearing 6 a toprevent the front bearing 7 from being fallen off the bearing housing 7.The step 7 a on the inner circumference of the bearing housing 7 has aform of “┐” for having a structure which supports a rear end portion ofthe front bearing 6 a mounted on a front end portion of the shaft 4. Thefront end portion of the shaft 4 is fixed to a spider 10 in the rearwall 200 of the drum 3, a region of the shaft 4 from a portion exposedin rear of the spider 10 to the front bearing 6 a has a bushing 11 ofbrass press fit thereon for prevention of rusting, and there is asealing member 12 on an outer surface of the bushing 11 for preventingingress of water toward the front bearing 6 a. There connector 16 isserration coupled to the rear end portion of the shaft 4 for connectionbetween the rotor 13 of the direct coupling type motor 5 and the shaft4, the rotor 13 is fixed to the connector 16 with fastening members 15c, and the stator 14, forming the direct coupling type motor togetherwith the rotor 13, is fixed to the rear wall 200 of the tub 2 inward ofthe rotor 13. As shown in FIGS. 3˜5, the rotor 13 of steel or steelalloy plate includes a bend part having a magnet setting surface 130formed along a circumferential direction of a sidewall 13 b extendedforward from a periphery of the rear wall 13 a of the rotor 13, forsupporting magnets 13 c fitted to a front portion of an inside surfaceof the rotor 13, and a hub 132 having a through hole 131 at a center ofthe rear wall 13 a of the rotor 13 so that a fastening member 15 a, suchas a bolt or the like, can pass through for coupling the rotor 13 to theshaft 4. An overall form of the rotor 13 is preferably formed bypressing. There are a plurality of cooling fins 133 each formed to havea preset length in a radial direction around the hub 132 of the rotor 13for blowing air toward the stator 14 during rotation of the rotor 13 forcooling heat generated at the stator 14. The cooling fins 133 are formedby lancing, to bend the cooling fins 133 at a right angle to the rearwall 13 a toward the opening to leave through holes 134 for ventilation.There is an embossing 135 between adjacent cooling fins 133 with a drainhole 136 therein for draining water. There are fastening holes 137 forfastening a connector 16 to the rotor 13 and positioning holes 138 forpositioning an assembly position of the connector 16 around the throughhole 131 in the hub 132 of the rotor 13 at fixed intervals, whichconnector 16 is serration coupled to an outer circumference of a rearend portion of the shaft 4 exposed in rear of the rear bearing 6 b. Theconnector 16 is formed of resin having a vibration mode different fromthe rotor 13 of steel or steel alloy plate. As shown in FIGS. 7˜9, theconnector 16 has fastening holes 162 to correspond to the fasteningholes 137 in the hub 132 of the rotor 13 around a circumferentialdirection of the a peripheral region and a dowel pin 160 betweenadjacent fastening holes 162 as a unit with the connector 16 forinsertion in the positioning hole 138 in the rotor 13 for self alignmentof the fastening holes 137 and 162 in the rotor 13 and the connector 16,respectively. The connector 16 has a serration in an insidecircumference of the hub 163 matched to the serration in the rear end ofthe shaft 4, and reinforcing ribs 161 on outer circumference of the hub163 for reinforcing the hub 163. There is a hub 201 on the rear wall 200of the tub 2 having the bearing housing 7 inserted therein when the tubis injection molded, and fastening bosses 202 on an outer side of thehub 201 along a circumferential direction at fixed intervals forfastening the stator 14 to the rear wail 200 of the tub 2. There is asupporter 17 between the rear wall 200 of the tub 2 and the stator 14,of a form almost identical to an outline of the rear wall 200, fixed tothe tub 2 rear wall 200 when the stator 14 is assembled for supportingthe stator 14 and maintaining concentricity of the stator 14. Once thesupporter 17 is fastened to the support fastening bosses 204, a fore endof the supporter 17 is brought into close contact with an inside of ribs203 at one side of the tub rear wall 200 and a rear end thereof isbrought into close contact with an outer circumference of a rear end ofthe bearing housing 7 which is not enclosed by the hub 132, but exposed,thereby the supporter 17 supporting the stator 14 and maintaining aconcentricity of the stator. In the meantime, as shown in FIGS. 3 and 6,the stator 14 includes a ring formed frame 140, a coil 142 wound aroundeach of winding parts 141 on an outer circumference of the frame 140,and fastening ribs 143 on an inside of the frame 140 for fastening thestator 14 to the tub rear wall 200.

In the meantime, referring to FIG. 9, there is an “└” formed step 900 bat an inner end portion of the bearing bracket 9 fixed to the tub rearwall 200 to cover an outer side of the rotor 13. And, there is a rearbearing fixing member 15 b at an rear end of the shaft 4 for supportinga rear surface of the shaft 4 to prevent the rear bearing from beingfallen off the shaft 4.

The operation of the driving unit in a drum type washing machine inaccordance with a second preferred embodiment of the present inventionwill be explained. Upon causing rotation of the rotor 13 by making acurrent to flow to the coils 142 of the stator 14 in a sequence underthe control of a motor driving controller(not shown) fitted on a panel,the shaft 4 serration coupled with the connector 16 fixed to the rotoris rotated, together with the drum 3 as the power is transmitted to thedrum 3 through the shaft 4.

In the meantime, the drum type washing machine in accordance with thesecond preferred embodiment of the present invention driven thus servesas follows. Alike the first embodiment of the present invention, sincethe tub 1 is formed of a plastic with an excellent heat resistance, thetub 1 is light and has a good formability as the tub 2 is injectionmolded. Since the bearing housing 7 is formed of a metal, such as analuminum alloy and the like, the bearing housing 7 is applicable to adrum type washing machine having a drying cycle as the bearing housingshows no thermal deformation. And, since the metallic bearing housing 7is formed integrated with the tub 2 by inserting the bearing housing 7in the hub 201 on the tub rear wall 200 before the tub 2 of plastic isinjection molded, a separate step for assembling the bearing housing 7to the tub rear wall 200 can be omitted, which simplifies an assemblyprocess, that reduces assembly man-hours. The step 7 a in an innercircumference of a front portion of the bearing housing 7 in the secondembodiment of the present invention supports a rear end of the frontbearing 6 a mounted on an outer circumference of the fore end portion ofthe shaft 4. That is, the “┐” formed step 7 a in a front portion of aninner circumference of the metallic bearing housing 7 of the presentinvention permits to support the front bearing 6 a without being fallenoff the bearing housing 7. And, the “└” formed step 900 b in an endportion of an inner circumference of the metallic bearing bracket 9covering an outer side of the rotor 13 fixed to the tub rear wall 200permits to support a front end of the rear bearing 6 b mounted on therear end portion of the shaft 4, and the rear bearing fixing member 15 bon the rear end surface of the shaft 4 prevents the rear bearing 6 bfrom being fallen off the shaft 4.

In the meantime, in the second preferred embodiment of the presentinvention, since the front bearing 6 a is mounted in the bearing housing7 having insert injection molded in the tub 1, and the rear bearing 6 bis mounted in an inside of a center portion of the bearing bracket 9, adistance between the front and rear bearings 6 a and 6 b on the shaft 4becomes greater, between which the rotor is mounted. The greaterdistance between the front and rear bearings 6 a and 6 b permits towithstand a load caused by imbalance of laundry in the drum 1 duringspinning better, and a supporting force to the rotor 13 is enhanced asthe rotor 13 of the motor is mounted between the front and rear bearings6 a and 6 b. Alike the first preferred embodiment of the presentinvention, in the second preferred embodiment of the present invention,the brass bushing 11 press fit to the region from the exposed portionoutside of the spider 10 of the shaft 4 to the front bearing 6 aprevents rusting of the shaft 4. And, alikely, the sealing member 12outside of the bushing 11 prevents ingress of water toward the bearing.

Alike the first preferred embodiment, as shown in FIGS. 3 to 6, the bendpart having the magnet setting surface 130 is formed along acircumferential direction of the sidewall 13 b extended forward from aperiphery of the rear wall 13 a of the rotor 13, for supporting themagnets 13 c when the magnets 13 c are fitted to an inside surface ofthe rotor 13, to fabricate the rotor with easy. Alike the firstpreferred embodiment of the present invention, in the second preferredembodiment of the present invention, the plurality of cooling fins 133around the hub 132 of the rotor 13 in a radial direction with a lengthblow air toward the stator 14 during rotation of the rotor 13 forcooling down a heat generated at the stator 14. The cooling fins 133 areformed by lancing, to direct toward the opening of the rotor 13, and toleave through holes 134 for ventilation. Since the rotor 13 is formed ofsteel or steel alloy plate by pressing, which shortens a fabricationtime period significantly, a productivity is improved. The embossing 135between the adjacent cooling fins 133 of the rear wall 13 a of the rotor13 improves an overall strength of the rotor 13, and the drain hole 136in the embossing 135 drains water.

In the meantime, the fastening holes 137 for fastening the connector andthe positioning holes 138 for fixing an assembly position of theconnector 16 around the through hole 131 in the hub 132 of the rotor 13permits an easy assembly of the connector 16 to the rotor, whichconnector 16 is serration coupled to the outer circumference of the rearend portion of the shaft 4. That is, once the dowel pins 160 on theconnector 16 are inserted in the positioning holes 138 in the rotor 13,the fastening holes 137 and 162 in the rotor 13 and the connector 16 arematched automatically, and by fastening the fastening members 15 cthrough the fastening holes 137 and 162, the connector 16 and the rotor13 can be assembled with easy. The connector 16 serves to damp vibrationfrom the rotor 13 to the shaft 4 as the connector 16 injection molded ofa resin has a different vibration mode from the rotor 13 of steel orsteel alloy plate. The serration 164 in the inner circumference of thehub 163 of the connector 16 is fit to the serration 400 in the rear endportion of the shaft 4, to transmit the rotating force of the rotor 13to the shaft, directly. The reinforcing ribs 161 on an outercircumference of the hub 163 of the connector 16 reinforce the hub 163.

In the meantime, the fastening bosses 202 along a circumference on anouter side of the hub 201 on the rear wall 200 of the tub 2 at fixedintervals permits to fix the stator 14 to the rear wall 200 of the tub 2by using the fastening boss 202. The supporter 17 between the rear wall200 of the tub 2 and the stator 14 having a form almost identical to theoutline of the rear wall 200 for being fixed to the rear wall 200 of thetub 2 when the stator 14 is fastened permits the stator 14 beingsupported and maintained of concentricity. That is, the front end of thesupporter 17 is brought into close contact with an inside surface of theribs 203 at one side of the tub rear wall 200 and the rear end of thesupporter 17 is brought into close contact with the outer circumferenceof the rear end portion of the bearing housing 7 at a central portion ofthe tub rear wall 200, which can not be enclosed, but exposed, by thehub 132, such that the supporter 17 supports the stator 14 as well asmaintains a concentricity of the stator 14.

The structure of a driving unit in a drum type washing machine inaccordance with a second preferred embodiment of the present inventionhas the following advantages.

The motor direct coupling structure of the drum type washing machine ofthe present invention permits to reduce repair, noise and power loss.

The bearing housing of metal in the drum type washing machine of thepresent invention shows no thermal deformation, that allows to apply toa product having a drying function.

The rotor of steel or steel alloy plate formed by pressing in the drumtype washing machine of the present invention requires a very shortfabrication time period, with an improved productivity, because thesteel or steel alloy plate pressing has an excellent formability.

And, the magnet setting surface on the rotor of the present inventionimproves a workability in fitting the magnets, and the drain holes, thecooling fins, and the through holes provided to the rotor can preventoverheating of the motor, improve a reliability of the motor, andprolong a lifetime of the motor.

And, the connector having a vibration mode different from the rotor inthe drum type washing machine of the present invention can attenuate thevibration transmitted from the rotor to the shaft, and the supporter cansupport the stator and maintain a concentricity of the stator.

Particularly, in the second preferred embodiment of the presentinvention, the greater distance between the front and rear bearingspermits to withstand a load caused by imbalance of laundry in the drum 1during spinning better, and a supporting capability to the rotor isenhanced as the rotor of the motor is mounted between the front and rearbearings.

Thus, by improving a structure of a driving unit of a drum type washingmachine, the present invention can reduce noise, repair and power loss,by improving a washing capability, can improve a product reliability,and, by improving workability in fabrication of components of thedriving unit, can improve a productivity.

It will be apparent to those skilled in the art that variousmodifications and variations can be made in the structure of a drivingunit in a drum type washing machine of the present invention withoutdeparting from the spirit or scope of the invention. Thus, it isintended that the present invention cover the modifications andvariations of this invention provided they come within the scope of theappended claims and their equivalents.

1. A washing machine, comprising: an outer tub formed of a moldedmaterial and configured to hold washing water, the tub including a rearwall and an integrally molded sidewall, wherein an inner side of therear wall of the tub includes a central portion that extends into thetub, and wherein an outer side of the rear wall of the tub has a centralportion that extends away from the tub; a bearing housing that ismounted on the rear wall of the tub; at least one bearing mounted in thebearing housing; a drum rotatably mounted inside the outer tub; a shaftcoupled to the drum and mounted in the at least one bearing in thebearing housing; and a motor coupled to the outer side of the rear wallof the tub and to the shaft, wherein the motor comprises: a statorcoupled to the outer side of the rear wall of the tub, and a rotorcoupled to the shaft and having a rear wall and a side wall thatsurrounds the stator, wherein a plurality of magnets are mounted on thesidewall, and wherein a plurality of cooling fins are formed on the rearwall of the rotor.
 2. The washing machine of claim 1, wherein thebearing housing is inserted injection molded into the rear wall of thetub.
 3. The washing machine of claim 1, wherein the outer side of therear wall of the tub includes at least one flat section to which thestator can be connected.
 4. The washing machine of claim 3, wherein therear wall of the tub incorporates at least one set of fastening bossesthat are integrally formed with the tub and that are configured toreceive fasteners that are used to mount the stator to the rear wall ofthe tub.
 5. The washing machine of claim 1, further comprising a rigidsupporter that is mounted between the rear wall of the tub and thestator.
 6. The washing machine of claim 5, wherein the rigid supporterabuts stiffening ribs that are integrally formed in the rear wall of thetub, and wherein the contact between the supporter and the stiffeningribs helps to locate the supporter during assembly of the washingmachine.
 7. The washing machine of claim 5, wherein the outer surface ofthe rear wall of the tub includes a plurality of fastening bosses thatare integrally formed with the tub and that are configured to receivefasteners that are used to mount the stator to the rear wall of the tub,wherein the fastening bosses have flat outer surfaces, and wherein thesupporter also includes flat portions that correspond to the flat outersurfaces of the fastening bosses, the flat portions of the supporteralso having apertures therethrough to allow fasteners to pass throughthe supporter so that the fasteners can couple the stator the fasteningbosses.
 8. The washing machine of claim 5, wherein the outer surface ofthe rear wall of the tub includes a plurality of fastening bosses thatare integrally formed with the tub and that are configured to receivefasteners that are used to mount the supporter to the rear wall of thetub, wherein the fastening bosses have flat outer surfaces, and whereinthe supporter also includes flat portions that correspond to the flatouter surfaces of the fastening bosses, the flat portions of thesupporter also having apertures therethrough to allow fasteners tocouple the supporter to the fastening bosses.
 9. The washing machine ofclaim 5, wherein the rigid supporter includes an outer circumferentialsurface that abuts stiffening ribs that are integrally formed in therear wall of the tub, and wherein the contact between the outercircumferential surface of the supporter and the stiffening ribs helpsto locate the supporter during assembly of the washing machine.
 10. Thewashing machine of claim 5, wherein a rear portion of the bearinghousing protrudes from the rear wall of the tub and is exposed, andwherein an inner circumferential surface of the supporter abuts theexposed rear portion of the bearing housing.
 11. The washing machine ofclaim 10, wherein a front portion of the bearing housing is insertedinjection molded into the rear wall of the tub.
 12. The washing machineof claim 5, wherein the supporter is generally conical in shape with thecentral portion of the supporter sloping away from the inside of thetub.
 13. The washing machine of claim 12, wherein a series of flat stepsare formed on the generally conically shaped supporter.
 14. The washingmachine of claim 1, wherein the rotor of the motor is formed of steel.15. The washing machine of claim 14, wherein an outer rim of the rotoris bent relative to the sidewall to increase the rigidity of the rotor.16. The washing machine of claim 15, wherein the outer rim is bent sothat a first portion of the outer rim extends approximatelyperpendicular to the sidewall of the rotor, and a second portion of theouter rim extends approximately parallel to the sidewall.
 17. Thewashing machine of claim 14, wherein an inner circumferential surface ofthe rotor comprises a rim that is bent to increase a rigidity of therotor.
 18. The washing machine of claim 17, wherein the innercircumferential surface of the rotor of includes a first bent portionthat extends substantially perpendicular to the rear wall of the rotor,and a second bent portion that extends substantially parallel to therear wall of the rotor.
 19. The washing machine of claim 1, wherein acentral portion of the rear wall of the rotor includes a flange portionhaving a plurality of mounting holes and a plurality of positioningholes, and wherein sidewalls of the positioning holes extend above orbelow the rear wall of the rotor, and wherein the motor furthercomprises a connector that is coupled between the shaft and the rotor,the connector including a plurality of fastening holes and a pluralityof positioning projections that are integrally formed with theconnector, wherein the fastening holes and the positioning projectionsare formed around the circumference of the connector such that thefastening holes align with the mounting holes on the rotor and thepositioning projections extend into the positioning holes on the rotorwhen the connector is coupled to the rotor.
 20. The washing machine ofclaim 19, wherein the connector is formed of an electrically insulatingmaterial.
 21. A washing machine, comprising: an outer tub formed of amolded material and configured to hold washing water, the tub includinga rear wall and an integrally molded sidewall; a bearing housing that isinsert injection molded into the rear wall of the tub; at least onebearing mounted in the bearing housing; a drum rotatably mounted insidethe outer tub; a shaft coupled to the drum and mounted in the at leastone bearing in the bearing housing; and a motor coupled to the outerside of the rear wall of the tub and to the shaft, wherein the motorcomprises: a single stator with wire windings, wherein the stator iscoupled to the outer side of the rear wall of the tub, and a rotorcoupled to the shaft and having a rear wall and a side wall integrallyformed of steel, wherein the sidewall surrounds the stator, and whereina plurality of magnets are mounted on the sidewall.
 22. The washingmachine of claim 21, wherein the stator includes a frame made of anelectrically insulating material.
 23. The washing machine of claim 22,wherein the frame comprises a plurality of fastening ribs that ate usedto couple the stator to the rear wall of the tub such that the stator iselectrically insulated from the tub.
 24. The washing machine of claim21, wherein the stator includes a frame having a plurality of fasteningribs that are used to couple the stator to the tear wall of the tub. 25.The washing machine of claim 21, wherein an inner side of the rear wallof the tub includes a central portion that extends into the tub, andwherein an outer side of the rear wall of the tub has a central portionthat extends away from the tub.
 26. The washing machine of claim 21,wherein the stator includes a frame having a plurality of fasteningribs, and wherein a plurality of fastening bosses are integrally formedon the outer side of the rear wall of the tub, and wherein fasteners areused to couple the fastening ribs of the stator to the fastening bosseson the rear wall of the tub.
 27. The washing machine of claim 21,wherein at outer portion of the bearing housing extends from the teatwall of the tub and is exposed.
 28. The washing machine of claim 21,further comprising a rigid supporter that is mounted between the rearwall of the tub and the stator.
 29. The washing machine of claim 28,wherein the rigid supporter abuts stiffening ribs that are integrallyformed in the rear wall of the tub, and wherein the contact between thesupporter and the stiffening ribs helps to locate the supporter duringassembly of the washing machine.
 30. The washing machine of claim 28,wherein the outer surface of the rear wall of the tub includes aplurality of fastening bosses that are integrally formed with the tuband that are configured to receive fasteners that are used to mount thestator to the rear wall of the tub, wherein the fastening bosses haveflat outer surfaces, and wherein the supporter also includes flatportions that correspond to the flat outer surfaces of the fasteningbosses, the flat portions of the supporter also having aperturestherethrough to allow fasteners to pass through the supporter so thatthe fasteners can couple the stator the fastening bosses.
 31. Thewashing machine of claim 28, wherein the outer surface of the rear wallof the tub includes a plurality of fastening bosses that are integrallyformed with the tub and that are configured to receive fasteners thatare used to mount the supporter to the rear wall of the tub, wherein thefastening bosses have flat outer surfaces, and wherein the supporteralso includes flat portions that correspond to the flat outer surfacesof the fastening bosses, the flat portions of the supporter also havingapertures therethrough to allow fasteners to couple the supporter to thefastening bosses.
 32. The washing machine of claim 28, wherein the rigidsupporter includes an outer circumferential surface that abutsstiffening ribs that are integrally formed in the rear wall of the tub,and wherein the contact between the outer circumferential surface of thesupporter and the stiffening ribs helps to locate the supporter duringassembly of the washing machine.
 33. The washing machine of claim 28,wherein a rear portion of the bearing housing protrudes from the rearwall of the tub and is exposed, and wherein an inner circumferentialsurface of the supporter abuts the exposed rear portion of the bearinghousing.
 34. The washing machine of claim 28, wherein the supporter isgenerally conical in shape with the central portion of the supportersloping away from the inside of the tub.
 35. The washing machine ofclaim 34, wherein a series of flat steps are formed on the generallyconically shaped supporter.
 36. The washing machine of claim 21, whereinan outer rim of the rotor is bent relative to the sidewall to increasethe rigidity of the rotor.
 37. The washing machine of claim 36, whereinthe outer rim is bent so that a first portion of the outer rim extendsapproximately perpendicular to the sidewall of the rotor, and a secondportion of the outer rim extends approximately parallel to the sidewall.38. The washing machine of claim 21, wherein an inner circumferentialsurface of the rotor comprises a rim that is bent to increase a rigidityof the rotor.
 39. The washing machine of claim 38, wherein the innercircumferential surface of the rotor of includes a first bent portionthat extends substantially perpendicular to the rear wall of the rotor,and a second bent portion that extends substantially parallel to therear wall of the rotor.
 40. The washing machine of claim 21, wherein acentral portion of the rear wall of the rotor includes a flange portionhaving a plurality of mounting holes and a plurality of positioningholes, and wherein sidewalls of the positioning holes extend above orbelow the rear wall of the rotor, and wherein the motor furthercomprises a connector that is coupled between the shaft and the rotor,the connector including a plurality of fastening holes and a pluralityof positioning projections that are integrally formed with theconnector, wherein the fastening holes and the positioning projectionsare formed around the circumference of the connector such that thefastening holes align with the mounting holes on the rotor and thepositioning projections extend into the positioning holes on the rotorwhen the connector is coupled to the rotor.
 41. The washing machine ofclaim 40, wherein the connector is formed of an electrically insulatingmaterial.
 42. A washing machine, comprising: an outer tub formed of amolded material and configured to hold washing water, the tub includinga rear wall and an integrally molded sidewall; a bearing housing that isinserted injection molded into the rear wall of the tub, wherein a rearportion of the bearing housing extends from the rear wall of the tub andis exposed; at least one bearing mounted in the beating housing; a drumrotatably mounted inside the outer tub; a shaft coupled to the drum andmounted in the at least one bearing in the bearing housing; and a motorcoupled to the outer side of the rear wall of the tub and to the shaft,wherein the motor comprises: a single stator coupled to the outer sideof the rear wall of the tub and having a wound core, and a rotor coupledto the shaft and having a rear wall and a side wall that surround thestator, wherein a plurality of magnets are mounted on the sidewall. 43.The washing machine of claim 42, wherein the stator includes a framemade of an electrically insulating material.
 44. The washing machine ofclaim 43, wherein the frame comprises a plurality of fastening ribs thatare used to couple the stator to the rear wall of the tub such that thestator is electrically insulated from the tub.
 45. The washing machineof claim 42, wherein the stator includes a frame having a plurality offastening ribs that are used to couple the stator to the rear wall ofthe tub.
 46. The washing machine of claim 42, further comprising a rigidsupporter that is mounted between the rear wall of the tub and thestator.
 47. The washing machine of claim 46, wherein the rigid supporterabuts stiffening ribs that are integrally formed in the rear wall of thetub, and wherein the contact between the supporter and the stiffeningribs helps to locate the supporter during assembly of the washingmachine.
 48. The washing machine of claim 46, wherein the outer surfaceof the rear wall of the tub includes a plurality of fastening bossesthat are integrally formed with the tub and that are configured toreceive fasteners that are used to mount the stator to the rear wall ofthe tub, wherein the fastening bosses have flat outer surfaces, andwherein the supporter also includes flat portions that correspond to theflat outer surfaces of the fastening bosses, the flat portions of thesupporter also having apertures therethrough to allow fasteners to passthrough the supporter so that the fasteners can couple the stator thefastening bosses.
 49. The washing machine of claim 46, wherein the outersurface of the rear wall of the tub includes a plurality of fasteningbosses that are integrally formed with the tub and that are configuredto receive fasteners that are used to mount the supporter to the rearwall of the tub, wherein the fastening bosses have flat outer surfaces,and wherein the supporter also includes flat portions that correspond tothe flat outer surfaces of the fastening bosses, the flat portions ofthe supporter also having apertures therethrough to allow fasteners tocouple the supporter to the fastening bosses.
 50. The washing machine ofclaim 46, wherein the rigid supporter includes an outer circumferentialsurface that abuts stiffening ribs that are integrally formed in therear wall of the tub, and wherein the contact between the outercircumferential surface of the supporter and the stiffening ribs helpsto locate the supporter during assembly of the washing machine.
 51. Thewashing machine of claim 46, wherein an inner circumferential surface ofthe supporter abuts the exposed rear portion of the bearing housing. 52.The washing machine of claim 46, wherein the supporter is generallyconical in shape with the central portion of the supporter sloping awayfrom the inside of the tub.
 53. The washing machine of claim 52, whereina series of flat steps are formed on the generally conically shapedsupporter.
 54. The washing machine of claim 42, wherein the rotor of themotor is formed of steel.
 55. The washing machine of claim 54, whereinan outer rim of the rotor is bent relative to the sidewall to increasethe rigidity of the rotor.
 56. The washing machine of claim 55, whereinthe outer rim is bent so that a first portion of the outer rim extendsapproximately perpendicular to the sidewall of the rotor, and a secondportion of the outer rim extends approximately parallel to the sidewall.57. The washing machine of claim 54, wherein an inner circumferentialsurface of the rotor comprises a rim that is bent to increase a rigidityof the rotor.
 58. The washing machine of claim 57, wherein the innercircumferential surface of the rotor of includes a first bent portionthat extends substantially perpendicular to the rear wall of the rotor,and a second bent portion that extends substantially parallel to therear wall of the rotor.
 59. The washing machine of claim 42, wherein acentral portion of the rear wall of the rotor includes a flange portionhaving a plurality of mounting holes and a plurality of positioningholes, and wherein sidewalls of the positioning holes extend above orbelow the rear wall of the rotor, and wherein the motor furthercomprises a connector that is coupled between the shaft and the rotor,the connector including a plurality of fastening holes and a pluralityof positioning projections that are integrally formed with theconnector, wherein the fastening holes and the positioning projectionsare formed around the circumference of the connector such that thefastening holes align with the mounting holes on the rotor and thepositioning projections extend into the positioning holes on the rotorwhen the connector is coupled to the rotor.
 60. The washing machine ofclaim 59, wherein the connector is formed of an electrically insulatingmaterial.